Like shopping for most major pool equipment it can be hard to understand the correct way to determine what model, size, brand, etc. equipment is best for you and your pool. In this article we go over the three types of filters and how to determine what size filter your pool needs.
Before
you can choose the correct size swimming pool filter, you first need to
understand the types of filters that are offered. The residential swimming pool
industry primarily has three types of pool filters from which to choose.
There are pros and cons for
each type as well as differences in how well they filter particles from the
water (measured in microns - a human hair is about 60 microns). We will quickly
discuss the differences, advantages and disadvantages of each and then we’ll go
over the things to consider when choosing the right size filter for your
swimming pool.
- Cartridge Filters
- Pros:
- Popular with higher horse power
pumps as they can handle the most water flow.
- Easy to disassemble and reassemble.
- No back-washing.
- Cons:
- Needs a solution to properly clean
between pleats (acid not recommended).
- Water clarity not as clear as D.E.
filtered water – filters down to 10 microns.
- Replacement cartridge cost can be high.
- Sand Filters
- Pros
- Low maintenance – sand is only
replaced every few years.
- Cons
- Least effective filter type – only filters
to 20 microns, at best.
- Lower GPM rating compared to D.E.
and especially cartridge.
- Must back-wash filter.
- D.E. Filters
- Pros
- Filters to the smallest micron of
any filter type – less than 5 microns.
- Low cost for replacement grids.
- Back-washing optional.
- Best filter for removing algae.
- Cons
- Can be difficult to take apart and reassemble (excluding Quad D.E.).
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One of the best products to hit the industry in recent years is a
and other benefits of a D.E. filter while being easy to break
down and reassemble. This new innovative design is making
this model one of the most popular in the industry.
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Now
that you are more familiar with the different types of filters and the pros and
cons of each, we can discuss the best way to determine the correct size for
your application.
I
would like to start by saying that with pool filters, just as with salt chlorine systems, always go larger! You can’t go too
big. From all the backyards I’ve visited while in this business, I can easily
say that far more often than not, the pumps are too big and the filters are too
small. This should be just the opposite. This combination provides poor
circulation and inferior efficiency. Not to mention higher electric costs as
well as increased maintenance expenses from deteriorating filter components due
to excessive water flow that the filter can’t handle.
Positive
aspects of sizing a filter properly:
- Longer filter cycles (less work for you as you will need to clean the filter less often or less money spent if you pay for the service).
- Increased flow as the pump is not met with as much
resistance from a filter that is too small.
- Increased cleaning time if/when you face issues with
algae.
To make this decision an easy one, you'll need to:
- Determine the flow rate of your system - This is your pump’s rated
gallons per minute. (Or it can be calculated as GPM, less resistance).
You can also add a flow meter to know exactly what your flow rate
(in GPM) is.
For our example, let’s assume
- Your pump produces 70 GPM, after resistance
is accounted for.
- You want a D.E. filter because it
provides the clearest water.
Here
are the recommended residential flow rates for D.E. filters:
| 24 Sq. Ft. |
36 Sq. Ft. |
48 Sq. Ft. |
60 Sq. Ft. |
72 Sq. Ft. |
| 36 GPM |
54 GPM |
72 GPM |
90 GPM |
108 GPM |
In
this scenario, the 48 sq ft D.E. filter would suffice, but the better choice
for would be the 60 sq ft. This will give you optimum circulation, longer
cycles between filter cleanings and less maintenance overall. Every filter type
and size you consider will have a GPM rating for you to easily see which one
will be a good fit for your specific scenario.
Should
you still have questions or are uncertain, please feel free to give us a call
at 888-836-6025 and we’ll be more than happy to assist you.
